1. Field of the Invention
This invention relates in general to fire extinguisher sprinkler systems, and more particularly to a sprinkler head mounting system which allows adjustment of the sprinkler head relative to the ceiling through which the sprinkler head extends.
2. Description of the Prior Art
Automatic fire sprinkler systems have been used for many years in commercial and industrial establishments and in many areas, they are now being used in residential applications. There are several differences between residential sprinkler systems and those used in commercial and industrial applications. Among these differences are especially designed water spray patterns and increased operating speed which tests have shown as being necessary to control or extinguish fires in typical residences and to provide a greatly increased level of protection for human life.
In addition, considerable attention has been directed to the appearance of the sprinkler heads in order to make them aesthetically appealing to the homeowner or residential occupants. For this reason, the sprinkler heads are ideally mounted almost entirely within the ceiling and have only a relatively small portion of the sprinkler head depending from the ceiling into the room. Also, the escutcheons used are of relatively small plate-like configuration. Therefore, the sprinkler heads must be located much more precisely relative to the ceiling than is the case with commercial and industrial installations where appearance is of much less importance. Of course, the sprinkler head must not be excessively recessed relative to the plane of the ceiling lest the ceiling interfere with the desired water spray pattern. Likewise, the sprinkler head must not protrude excessively into the room or the desired aesthetic appearance will not be achieved. This poses some problems with an acceptable installation of residential sprinkler systems.
Sprinkler systems must be fully installed and pressure tested, with the system being inspected for leaks after a specific test period, and repaired if necessary. This can be a relatively simple task provided that it is done prior to installation of the ceiling and can be extremely difficult if it is accomplished subsequent to ceiling installation. For this reason, sprinkler systems are installed prior to installation of the ceiling and the plumber must make an educated guess as to just where the plane of the subsequently installed ceiling will be. Due to the non-precise nature of walls, ceilings and related construction, more often than not, the location of the sprinkler heads will not be located within the relatively small positioning constraints imposed upon residential system installations. Therefore, some vertical movement of the sprinkler heads will be required in many instances to properly locate the heads relative to a subsequently installed ceiling. Even after installation and sprinkler head repositioning has been accomplished, things can change, such as sagging of the ceiling, which requires further vertical repositioning or adjustment of the heads.
In situations where sprinkler head positioning deviates only slightly from the ideal location, a simple sliding movement of the escutcheon plate axially along the sprinkler head body may be all that is needed to achieve an aesthetically acceptable appearance. However, some types of sprinkler heads make no provisions for such adjustments, while in others this remedy is limited to small deviations of about 1/4 inches or so.
In cases where sprinkler head positioning deviates more than a minimal amount, one prior art technique used, is to remove the sprinkler head and reinstall it with a longer nipple, shorter nipple, or otherwise modifying the installation as necessary to achieve whatever vertical repositioning is needed. This technique is very undesirable due to the costly labor and material involved.
In an attempt to overcome the above installation problem associated with residential sprinkler systems, an adjustable extensible nipple assembly has been devised. The special nipple includes an outer casing which is threadingly attached to the sprinkler piping system so as to be disposed in a vertical attitude. The depending end of the outer casing is internally threaded and an inner tube is carried in the bore of the outer casing for threaded axial adjustment relative to the outer casing. The upper end of the inner tube has a pair of O-ring gaskets which form a leakproof seal within the bore of the outer case, and the lower end of the inner tube is internally threaded for mounting of the sprinkler head therein. Although this prior art adjustably extensible nipple assembly solves the problem of vertical sprinkler head relocation to match the plane of a subsequently installed ceiling, there are two basic problems associated with this nipple. The first problem is that the adjustable nipples rely on the pair of O-rings to provide the leak-proof seal, and O-rings deteriorate with time.
The second problem associated with these adjustable nipples is the cost. As is known, sprinkler systems are subject to rather stringent regulations, must be able to withstand high water pressure, water hammer and the like for indefinite periods of time, and then must be workable when and if needed. For these reasons, these adjustable nipples are precision devices which have undergone extensive testing and the like, and as a consequence are very expensive.
Therefore, a need exists for a new and improved sprinkler head mounting system which overcomes some of the problems and shortcomings of the prior art.